The invention relates to a foam fireplace construction. More particularly, the invention relates to a system which allows a fireplace to be conveniently and safely constructed using foam components, wherein such components may be provided in multiple modules which are subsequently assembled xe2x80x98on-sitexe2x80x99.
Wood burning fireplaces are generally constructed using bricks, stone, and mortar. These materials are used because of their non-flammability. Unfortunately, these materials are expensive and require skilled artisans to spend considerable time working at the site of installation to create the fireplace.
Although foam, especially polystyrene and polyethylene, holds great promise as a building material, its limitation lies in the difficulty of interfacing with other building materials. For example, common fasteners such as screws and nails cannot be used to attach other building materials to foam. They xe2x80x98pull outxe2x80x99 from the foam just as easily as they penetrate the foam.
The most common way in which foam is attached to other surfaces is with adhesives. The adhesives, however, only adhere to the outer surface of the foam. Accordingly, the strength of the joint relies upon the internal structural integrity of the foam. Such a joint may present reasonable resistance to shearing forces, but cannot resist much torsional loading against the joint. Such forces will have a tendency to xe2x80x98peel awayxe2x80x99 the foam at the joint. In addition, even in a suitable installation, adhesives have a tendency to weaken with age.
Foam has a further limitation in the context of fireplaces: it is not suited to being subject to an open flame or intense, concentrated heat. Upon exposure to the same, foam will melt, deform, and possibly burn. Ironically, foam is an excellent thermal insulator. Accordingly, the key to the effective use of foam in a setting which would otherwise subject the foam to intense heat requires a solution to the problem of interfacing the foam with fire resistant building products.
What is needed to allow a fireplace to be constructed largely using foam components is both a reliable system for protecting the foam with fireproof or fire resistant materials and a system for securely joining foam components or modules with other foam components or modules.
My prior U.S Pat. No. 5,661,929 discloses a system which allows a building material to be anchored to foam by inserting a metal channel into the foam, and then anchoring the building material to the metal channel using ordinary fastening devices, such as screws or nails. This system allows a variety of other building materials to be fastened to the foam using screws or nails, by fastening to the metal channel therein. This system provides a basis for the present invention""s attachment of fireproof board to the foam, and is incorporated herein by reference.
The attachment of foam blocks, components, or modules is not the primary focus of the present application. The present discussion, however, includes a detailed description of a system for the interconnection of the foam blocks, components, and modules of the present invention.
It is an object of the invention to produce a fireplace which is safe while being largely constructed from foam components. Accordingly the fireplace includes a foam firebox which is lined with fireproof or fire resistant boards which are anchored to the firebox to protect the same. Further, a double-walled flue extends through the chimney housing, having an inner tube and an outer tube. The outer tube is anchored to the foam. Air spaces between the outer and inner tubes, and well as between the outer tube and foam sufficiently insulate the foam chimney housing from hot gases escaping from the firebox through the flue.
It is another object of the invention to provide a fireplace which includes a base, a firebox, and a chimney housingxe2x80x94which are all constructed largely of foam, are finished in an aesthetically pleasing manner under controlled manufacturing conditions, and are subsequently interconnected at the installation site. Accordingly, the base, firebox, and chimney housing have connector sets which interface to create a simple and permanent interconnection attachment system. Accordingly, the system employs mateable connection devices, which are partially submerged within the foam shapes and are subsequently mated to attach the foam shapes.
It is a further object of the invention to provide an attachment system that has superior strength for ensuring a permanent connection between the base, firebox, and chimney housing components. Accordingly, each connection device has a transversely extending flange, which significantly anchors the connection device within the foam and resists pulling out of foam and detaching the components.
It is a still further object of the invention to provide superior tensile strength at the joint between the foam components which resists detachment of the connection devices. Accordingly, by at least one embodiment, one of the connection devices has a male component which forms a permanent part thereof and which selectively secures directly in the open end of a female connection device, providing a direct attachment between the connection devices.
It is a still further object of the invention to provide superior anchoring within the foam for the critical attachment of the chimney housing and firebox. Accordingly, by one embodiment of the connector set, the transverse portion of one of the connection devices has a complex shape, such as a xe2x80x98dutch hatxe2x80x99 shape, which increases the surface area of the foam against which the connection device is anchored and distributes tensile forces in several directions to prevent the chimney housing and firebox from detaching.
It is yet a further object of the invention to provide a system which has superior strength, yet is inexpensively manufactured. Accordingly, the foam components are inexpensive, and are able to be assembled in accordance with the present invention such that they have superior structural integrity.
The invention is a fireplace construction which includes a base, a firebox, and a chimney housing which are substantially constructed of foam. The firebox is lined with fire resistant boards by anchoring the boards to an insert extending through the foam. The chimney housing includes a double walled flue which has an inner tube for venting hot gases from the firebox, an outer tube which anchors to the foam chimney housing and creates an air space between the inner tube and outer tube to protect the chimney housing from the hot gases escaping through the inner tube. The firebox, base, and chimney housing are attachable upon installation by connector sets which include connection devices which extend within the foam of the firebox, base, and chimney housing. The firebox, base, and chimney housing are mated by attaching the connection devices embedded therein to each other.
To the accomplishment of the above and related objects the invention may be embodied in the form illustrated in the accompanying drawings. Attention is called to the fact, however, that the drawings are illustrative only. Variations are contemplated as being part of the invention, limited only by the scope of the claims.